DESCRIPTION (APPLICANT'S ABSTRACT): It is proposed a randomized, blinded, controlled trial comparing vestibular rehabilitation (VR) to Tai Chi. Our overall goal is to explore whether, and if so, how TC can improve functional, dynamic stability in persons with vestibulopathy (VSP). It is hypothesized that the TC group will demonstrate significantly greater improvement in performing functional activities than the VR group. Specific Aims #1: To determine the relative neuro-biomechanical benefits of TC and VR. Sixty subjects will be randomly assigned into either TC instruction or VR. Both treatment groups will receive identical duration treatment once a week for 10 weeks, with supplemental home exercises. It is hypothesized that I) TC improves whole-body dynamic locomotor stability more than does VR; 2) TC improves gait coordination during planned and unplanned obstacle encounters more than does VR; 3) TC improves whole-body speed related movement control more than does VR. #2: To determine which biomechanical measures best demonstrate TC and VR motor control and coordination improvements. It is proposed to quantify VSP patients' motor control and coordination using muscle power flow, gaze (eyehead) stability, and whole-body dynamic stability during standing, locomotion and balance perturbations. It is hypothesized that 1) The TC group will demonstrate power flow more similar to healthy individuals than those receiving VIA during locomotion and balance recovery followingperturbation; 2) The TC group will demonstrate greater improvements in intersegmental movement coordination, which in turn, translates into improved gaze and whole-body stability, than the VR group. #3: A) To determine whether TC improves psychological status, including fear of falling. B) To determine the association between both psychological variables and TCM medical diagnosis, and their predictive value about response to TC or VR. It is hypothesized that TC will improve both fear of falling and other psychological scores more than VR. It will also be diagnosed each patient according to traditional Chinese medicine (TCM) diagnostic categories to determine whether any TCM category is more likely to be associated with improvements in either group. The latter aim is purely exploratory and descriptive in nature.